Payback
by Garrae
Summary: What would have happened if Beckett gave in to Castle's pleading and bought him at the auction in 1.07, Home is Where the Heart Stops? Shamelessly frivolous and fluffy. Note M rating: also a Summer Hiatus Kink Meme fill. Characters belong to ABC and Marlowe.
1. Chapter 1

**This is not my fault. It's for Ronin Blackwing, who suggested something just a little different but this is what came to me and wouldn't go away no matter how hard I tried. Hope you like it anyway, Ronin! For everyone else, this is all Ronin's fault. Address complaints to them.**

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**Chapter 1: Going once**

She'd been furious when the dress turned up. She doesn't need help (even if she'd had nothing to wear – how is she _saying_ that: she always has the right thing to wear) dressing. Fury had lasted right till the moment she looked at it. Perfect colour – she absolutely adores that shade of red. Blood red may not be the most appropriate shade given her profession – blood on the floor means something's badly wrong, though as long as it's not hers it's generally okay - but the colour suits her. Perfect size – if she thought about it, that would be really, really worrying. He's never put so much as a finger on her, so how on earth can he judge her size that accurately? Observation clearly means more than she thought. It's not just her work attributes he's been observing. Not that he'd be shy of continuing his _observations_ by putting a – or all ten – fingers on her. That's been very clear from moment one. Do not think about that, Kate. Now is not the time. She's working. Perfect style. She may not be _well_-endowed, but she's got enough there to fill some very pretty lingerie.

Not that she can wear it, under this dress. Not only is it strapless, and plunging to boot, (even the boys looked at her with admiration: they've never looked at her like that before and if they value their lives they never will again) but the designer left out any concept of a back panel in favour of some very, very sexy lacing. It's so low in back that she couldn't even wear a bra designed for backless dresses. Just putting it on made her feel naughty in ways that puddle down low in her body. She thinks she's doing a good job of hiding those feelings. She is, after all, here to work. Castle, on the other hand, is not hiding his feelings at all. It's very unreasonable that he's tall enough to look downward like that. She's certain that he's enjoying the view. He's certainly spending enough time staring at it. Much more staring and the dress will incinerate. That'd be embarrassing. Even when she'd modelled lingerie all those years ago she'd not needed to go topless. If they weren't at work, now… well, it wouldn't necessarily be a problem. Admiration is always nice. What? Left field calling. That was a wholly inappropriate thought. Of course it would be a problem.

It would be a lot easier to work if Castle didn't look so amazingly good (_you mean sexy, Kate_) in a tux. All men look better in tuxes. But it's entirely unfair for one particular man to look so… well, edible. Mmmmm. She could eat him right up. Then he could eat her right up – _stop_. Now. That thought is _not_ conducive to catching a killer.

A line up with this lot would blow the precinct cameras, with all the glitter from all the bling. Well. It's not bling, because it's real, and expensive. When it's this much of New York's high society having an event their adornments don't get described as bling. Even if it is. She's perfectly sure that no-one here talks street slang. Not that she can talk about bling, or lack thereof. The dress sparkles, the necklace Martha lent her sparkles, and she's fairly sure that her eyes are sparkling. Nothing to do with her response to Castle's eyes. Which are also sparkling. Quite ridiculously attractively.

She glares around the room, at a reduced wattage in order not to frighten the society belles and beaux. She'd rather be interrogating the lot of them, on home ground. Especially, she'd like to interrogate the woman who's picked off Castle at the bar and appears to be interrogating him. This is not a date, but it's still very rude to monopolise someone else's escort. From the hunted look on his face, he needs rescued. Well, he'll need to rescue himself, because Beckett needs all her rescuing abilities to evade the woman – or barracuda, from the expensively dentally enhanced toothy smile – who's just swum up to her in the hope of finding out how she, Beckett, managed to get her – the implication is _unworthy_ – hands on Castle. Well, she hasn't. Got her hands on him, that is. Nor he on her. Though she's absolutely sure he'd be very enthusiastic if she suggested it. And her hands are thoroughly worthy. Which thought is _not helping_ her find a lead.

Nor is this. Castle clearly has rather more talents than tossing out unlikely theories and being irritating. (though she secretly enjoys the effort he puts into irritating her. It amuses her, and she knows that he knows that her snark in return is because he's become part of the team. Not that she's telling him that.) The man can dance. Someone that big usually can't. Or they're too…forceful. It's not a sixties hop. She doesn't need flung around. In this dress, it might cause a wardrobe malfunction. She couldn't find her modelling tape. She used the last of her duct tape to fix a wire under a shelf.

She has to remember that she's working. Because otherwise she might just quite unreasonably and stupidly succumb to the temptation to move a little closer in – he's not pulling her in, but it's perfectly obvious that if she evinced the slightest desire to be closer he'd oblige – lay her head on his shoulder, maybe undulate a very little (more is definitely tacky, in public – _what?_) and let the warmth of that large hand keep her there against a rather impressive body. Sadly, she can't. She's working, dammit! It's the first time ever she wishes she wasn't. That feels very nice. Very nice indeed. Why's she not done this before? What the hell is she thinking? She needs to get her mind (and body) under control, stat.

Oh. Yeah. Because this is his milieu not hers. Rich playboys, bored rich women, paid for escorts of both sexes. She doesn't belong here. Paparazzi and diamonds aren't her scene. Though from the look Castle's still giving her, it's not his either. She's fairly certain (through his lack of control of his physical – er - reactions) that his scene currently encompasses her, the dress, a floor covered in said dress, and a bed. Mmmm. She could cope with that. What? That came out of left field too. She couldn't. Definitely not. And now his fingers are misbehaving very slightly. Nothing indiscreet. Just as well. She doesn't need to be on page six. PR is not an advantage, in her line of work. She'll get quite enough grief from the boys tomorrow without adding that. But his fingertips are moving. Gently. Extraordinary, how much heat is coming from his fingertips. It's all concentrating down low. He shouldn't be doing that. She shouldn't be enjoying it.

Well, she was enjoying it. Being abandoned on the dance floor really does not do it for her. Very bad manners. She'd never previously thought he was bad-mannered. Annoying, flirtatious, and inappropriately mannered, yes. Bad-mannered, no. He's generally very well-mannered. Too much so, when it comes to exploring doors with bad guys behind them. He shouldn't be trying to open them for her. Spoils the surprise.

Oh. Ah. He's found her a lead. _That_ does it for her. Well. Helps. Oh yes. Oh no. Another left field thought. But she does like success. Oh. It's not a lead. It's a confusion – that's not English. She speaks better English than that. Who is this old man, anyway? Apart from a very charming flirt. Even better than Castle, in fact. She should tell him that. Castle, that is. He's so funny when he's spluttering in outrage. She's just about to do so when the lights go up on stage and – oh my God, it's Martha, and this old man is snickering, and Castle looks utterly, utterly dumbfounded – he must be, he can't even speak, which is _unheard _of – and she just _knew_ she liked this man whoever he actually is: he's got charm, personality, wit – and he's reduced Castle to speechlessness. Maybe he - this old man - would like to come for a drink sometime. He's really interesting.

Her respect for Martha's taken a high jump – not to mention a pole vault – upwards, too. No wonder Castle had been so flustered when she'd told Martha where they were going. She and this old man – Powell, that's it – must have planned this in short order. Still, surely it can't be as embarrassing as Castle's current level of cringe would indicate. Unless there's some history she doesn't – ah. Hold on a moment. Something's nagging at her mind. Powell. Powell. Why does that name ring a bell in the Castle context. Powell … jewels…confusion…accusations – oh my lord. _This _is the Powell to whom Castle dedicated a book. He would indeed be _really_ interesting to talk to over a drink. Of the precinct coffee, in Interrogation. If only she had some proof. Or evidence. Or even half a reason to suspect him. His eyes are twinkling irresistibly mischievously at her. She's sure this Powell knows _exactly_ what she's thinking. She twinkles back, only marginally diluted by a soupcon of glare, and turns her attention to the stage. Martha's stage presence is phenomenal. She sees where Castle gets his personality traits from. Though in his case it's at least as much that he's far too sexy for his own good. Or hers. _Stop that_. She's still working. Dammit. No. Not dammit. Not at all. Get the damn fielder out of left field. She doesn't have time for this.

Charity auction time. Let's show everyone how rich we are. Or in her case, aren't. She won't be bidding. She'd need to win the lottery. Twice. Given her luck, several million times. She's never so much as won a packet of sweets in the lucky dip. Everyone wins on the lucky dip. Except her. She got the plastic ruler. Madison got the box of chocolates. And wouldn't share, either. Not that Beckett's bitter. What's today's star prize? Week in the Hamptons? Month on Barbados? First class flights to Hawaii? How about something useful? A confession to murder? She'd take that one. Maybe Castle would subsidise her bids for that one. She should ask him. She's just about to share the joke when Powell says –

"Payback." Castle looks first adorably (what? Not adorable. Really not.) bemused and then horrified – and then his mother opens up.

"Thank you for that warm welcome. The first item on our list is a signed first edition of Storm Season, written by, well, by my son. There he is. Wave, darling, so everyone one can see you. Oh, isn't he handsome?" Castle is, well, gibbering. It's hysterically funny. He's embarrassed. So he should be. How come his _mother_ needs to get him dates still? Beckett thought he was quite capable of doing it himself. Mind you, if he's been as successful with others as with her maybe he does. Maybe, given what Castle's said about her, his mother's hoping for a double date. She'll get a rich silver surfer and Castle will get a pretty younger woman. Hmm. That is an unpleasantly unwelcome unpleasant thought. Surely she's not bothered by Castle being auctioned? Oh. She is. Well, she shouldn't be. Really. She has no right to be bothered. So she can't be. There. Sorted.

"My still single son, ladies. So, as a special bonus, the winning bidder will also receive an enchanting evening in his company. Alright, ladies, that's the best I can do. The rest is up to you. Do we have an opening bid?"

Bidding's quick, and high. Castle's desperately trying to hide. When he's not cowering, he's pleading with Beckett to bid on him. When a rather handsome man bids, the pleas take on an air of terror. When it's a diamond encrusted senior (Beckett's sure that she's got diamonds soldered into the wrinkles in her forehead to replace her tiara) his pleas reach a falsetto squeak.

"Look, I have money," he whimpers. Whimpers. It's like listening to a smacked puppy. "Anything you pay, I'll pay you back."

Beckett can't stop sniggering. But then he turns enormous, pathetic, desperate blue eyes on to her. That wouldn't work. What does work is the unseen hand sliding over the bare skin of her back and down to her ass. She conceals her wriggle by main force. He must be desperate. Trying to suborn her with sex? Clearly he's willing to risk losing a hand to get her to bid. Just maybe this could have some serious advantages.

"Anything? Well now, Castle. Anything, hmmm?" She smirks. "Deal. I'll bid whatever it takes to win you. Then we'll talk about what the payback might be. Of course you'll cover the money, won't you? The payback's on top of that." He nods, frantically.

"Just get on with it, Beckett. Please? Before one of these senior sharks takes a bite out of me. Have you seen their smiles? I feel like I'm going to _be_ dinner not taking someone out for dinner. No limit. Whatever you need to spend, I'll pay."

Beckett raises her hand. Martha clocks it, and ups the bid to $5,000. The diamond-doused senior doesn't like it. Another row of dentures appears on her face. $6,000. Beckett bids $7,500. Senior pauses, grimaces, eyes Castle up and down, stopping just south of his cummerbund. $8,500. He winces. "Save me, Beckett."

"What, like I do every time you won't stay in the car? You got yourself into this."

"You promised," he wails. He sounds like he's five and she's reneging on giving him a trip to the carnival. She raises her hand again, signals $10,000. He's so pathetically dependent on her saving him – and the prospect of payback is just so good - that she can't resist. The senior looks pitch blackly at her. If looks could kill, Ryan and Esposito would be arresting that woman over Beckett's cold dead corpse. Though she'd look damn good, in this dress. If she weren't dead, of course. That's a stupid thought. Focus, Beckett. It's undoubtedly the location of Castle's hand that's destroying her focus. She should take a step away. She does. And it's got nothing to do with the extremely interested expression on Martha's face. Nothing at all.

Looks like she's won. Castle's breathing sighs of relief down her neck. It tickles. She wriggles. It's nothing to do with the errant thought of how it feels to have Castle that close. Not. She'd stepped away. She _had_. So how come he's back right behind her again?

"Thank you, Beckett. Thank you. Did you _see_ how she was looking at me? I haven't been that scared since you tried to kill me over the Heat name. In fact, even then I wasn't that scared." Beckett slowly raises one eyebrow.

"And you're not scared now? You owe me, Castle. Big time. You have _no idea_ how I'm going to make you pay." He's staring down at her. Well. Down the front of her dress, again. She can see a whole book's worth of inappropriate suggestions rising in his face. She's sure they're inappropriate. A whole book's worth of inappropriate suggestions of her own wriggle down her synapses and start invading other areas.

Impropriety of any sort by any person is abruptly cancelled by a lead. Lead, well, leads (aargh!) to an arrest. Arrest leads to cells, and then, thankfully, to sleep. She'll get the dress cleaned tomorrow. No. Monday. Tomorrow is Sunday. She thinks. It all got a bit confused, what with fundraisers and auctions and then arrests. She seems to have lost a day. Anyway. Better get it cleaned. Who knows how soon she might need it again?

Now. On to a much more pleasant thought. How's she going to make Castle pay for the bid? He's already handed over the money. He'll be taking her for dinner. She's sure he'll pick somewhere nice – but she'd better make sure it's discreet. She has still no desire at all to be on page six. She'll get quite enough hazing from the entire bullpen, starting and no doubt finishing with Ryan and Esposito, as soon as she shows up. But she really does not need to be the subject of hate tweets from Castle's extremely extensive fan base. Male and female, on the evidence of the auction. Anyway. Focus. What should she claim for getting Castle out of a tight spot. _Get him into a tight spot_, says an evil little voice in the back of her head. _Can't you think of one where you'd like him to be_? That's really not at all helpful. Not one iota helpful. Several tightly clenching muscles give her the lie. She has a nice cool shower and goes to bed. Sleep is punctuated by some decidedly and unhelpfully explicit dreams as to how she might make Castle pay up. She needs another nice cool shower in the morning. She hates cool showers.

Castle was clearly brought up well. She's barely finished her coffee before he's telling her about the arrangements for dinner. Either that, or he can't wait to get rid of the obligation. Dinner, and dancing, tomorrow night. Oh. Dancing? Again? Is this really a good plan? _What_ sort of dancing? _Where_? Dinner and slow dancing at a black tie establishment? How did this happen? She's the one who's supposed to be making him pay up. How does being manoeuvred into slow dancing with Castle count as _him_ paying up? That's more – looking at his face he knows it, too – like him taking shameless advantage. Well, two can play at that game. As soon as he's out of earshot she puts a hurry-up on the dry-cleaner and arranges to pick the dress up tonight. She's been manoeuvred into that too. He's perfectly well aware she doesn't have another dress. Well, it's stunning. She's quite happy to wear it again. Lots. And the effect it has on Castle is just a happy by-product. Not the main idea at all.

"I'm still thinking about how you can pay your debts, Castle." He smiles slowly and wickedly. That's not fair. "I could make you be silent for a whole day." He looks suddenly horrified. "Or a week." There's a strangled squawk. The boys' sniggers are clearly audible. "Or you could come and clean my apartment and do my washing and cook me dinner. I've always wanted a maid. Appropriately attired, of course."

There's a very _un_suppressed snort from Esposito and an even louder one from Ryan.

"Will you make him wear a frilly apron? Or a French maid outfit? How much will you pay to keep those photos off page six, Castle?" Beckett has a sudden visual brainworm of Castle in a black dress, white apron and silly little white cap and barely stops herself guffawing. Her splutters and purple face, however, don't do anything to conceal her thoughts.

Castle is impervious. In fact, he's smiling to himself. It looks very much as if a thoroughly dirty thought has crossed his mind. Asking him about it would undoubtedly be a huge mistake. It would. She goes to make coffee. Castle wanders after her. He's still got that filthy dirty smile. It gives her entirely the wrong idea about what she should have her lips on. Or he should. He looks her up and down, slowly.

"What?" she snaps.

"Just wondering…"

"What?" That was probably a really stupid question. Two seconds later, she knows it was.

"How do you know what a French maid outfit looks like, Beckett?" That's such an unfair thing to do. He is _not_ allowed to use that voice within a hundred yards of her. Or the precinct. Ever. It wiggles straight down her spine without waiting for permission. It says in every syllable _I'd like to see you dressed up_. Or possibly simply _I'd like to see you not dressed at all_. She makes her coffee with considerably more emphasis, forceful button-pressing and cup clanking than is entirely warranted by the machine. If she's looking at the buttons the heat in her face can't possibly be attributed to anything other than the milk steamer. She never blushes. Ever. And she is absolutely not considering the benefits of dressing up. At least, not as a _maid_. Servitude? No way. Though having Castle at her – er – service could be really, really - No. This is not a good thought. No. It's an excellent – _No_! It is _not_ an excellent thought.

She goes home as soon as it's politic to do so, picking up her dress on the way. (she strokes it when she hangs it up) Another cold shower seems indicated. At this rate, her electricity bill for this month will be halved. Her dreams are equally as unhelpful tonight as they were last night. Her morning shower is equally cold. Her day is equally full of ridiculous thoughts and speculations about how she should enforce payback. However since Castle doesn't show up, thankfully, (though she looks up – it's not hopefully, it's not - every time the elevator bell pings, which does _nothing _for her concentration) there's nobody to notice if she's just a little flushed. Just as well it's another paperwork day. Frequent lapses of concentration don't matter so much.

Before she gets home her phone chirps with a short text. _Car will collect you 7pm_.

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_Love to know your thoughts. _

_Totally frivolous fluff. There will be a total of four chapters - see, I can write short!_


	2. Chapter 2

**Chapter 2: Going twice**

The luxurious town car produces Castle, all dressed up again and looking just as deliciously edible as previously. He smoothly opens the car door for her, ensures in the best possible James Bond style that her dress is safely inside, and then when they're both installed turns to her, collects her hand and kisses it very much in the grand style. At least, it would be, except he's drawn a little pattern with his tongue on the back of her hand. She didn't expect that. She's sure that's not part of the etiquette playbook. It has a quite alarming effect on her. It seems that she has nerve connections all the way up her arm and down her body. She wriggles.

"Cold, Beckett?" He's still got her hand. Now his thumb is drawing little patterns. They're wriggling down her nerves too. This is ridiculous.

It's even more ridiculous when he promptly slips his arm around her.

"That'll keep you warm." Right. Warm. Not to say – hot. At this rate she'll be enforcing her payback before they've even got to dinner – no! She shouldn't waste an opportunity like that. She could have anything she wants from him, so why hurry it – _what?_ Is she seriously considering using up her payback on turning Castle into her toy? What's got into her? (A little voice says _you'd like him to get into you_. She ignores it, before she acts on it.) She wriggles, again. The arm tightens around her, and wraps her in more closely. It feels very nice. She tucks herself in closer. In this position, with him holding her hand and stroking it in a way that implies stroking other areas, the more she thinks about the many varieties of payback, the better the one that involves no clothes sounds. Even better than the one that involves him staying absolutely silent for, oh, a month? Wow. When did _that _change? Three days ago she'd have taken the silence. That would have been a mistake.

She shouldn't be thinking like this. But he looks delicious and smells delectable (maybe there's an additive in his aftershave that's making her think like this) and his arm round her feels absolutely right and if she were honest she's been thinking about what he might be like in more private circumstances for weeks and weeks and weeks and, well, what the hell, she just wants him. And his bad-boy reputation is very appealing, suddenly.

He's spent weeks and weeks flirting outrageously. He's spent weeks and weeks thinking that he's in control of that game. He's spent weeks and weeks telling her with and without words that he wants to go to bed with her. He's just run his tongue over her hand in a way that tells her very clearly that he wants to run it over several other areas. All of which are currently telling her brain that she should get on and arrange it. If he's going to issue invitations, he can't complain if she decides to accept.

Time to call his bluff.

But not just yet. A bit of winding up will do nicely. After all, he's winding her up. Certain locations are very wound up. Turnabout is fair play. If she really plays her hand well (or other areas) she could ensure that _payback_ lasts for a very long time. All day, and then night, in fact. And getting her meals made would be a bonus.

Mmmm. Yes. Dinner, dancing, winding up… payback. But she's not selfish. _How_ he delivers the payback is (largely: there are some things she doesn't like. In food and in bed.) up to him. She wiggles in a very particular way in order to tuck in further. She fits very nicely. Just like Castle fits that tux. Though certain areas are currently beginning to look just a little strained. Happened coincidentally close to her putting her hand on his knee. Accidentally, of course. The car took a corner a little fast. More than five miles an hour. So she _accidentally_ lost her balance, just a bit. So of course she needed to regain it. Totally unplanned. Really. And if her fingers are misbehaving very slightly, well, he started it, at the fundraiser.

It's possibly just as well that the car has stopped. She was seriously considering something a bit more than _misbehaviour_. Definitely a misdemeanour. Or possibly a felony.

Castle has the door open for her almost before she's undone her seatbelt and escorts her into the restaurant as if she's the Hope Diamond going on public display. It occurs to her that she's being _shown off_, in a very _look-what-I-got-isn't-it-fabulous_ way. That's…weird. Flattering, but weird. She'd been under the impression that the women with Castle showed _him_ off. In a _look-what-I-caught_ way. Captain Ahab had nothing on the women at the fundraiser. That's why she's here. Initially. She thinks smugly that Castle may be rethinking his reasons.

Dinner is superb. Conversation is witty, rapid and thoroughly enjoyable. Even the coffee is really, really good. Not that Castle seems to be paying much attention to the food. Or the wine. Or indeed the coffee. For some reason he seems a little distracted. She can't think why. Surely running her foot up and down his leg doesn't disconnect his brain? It can't have. It hasn't stopped him talking. That did, though. That's good to know. All she did was run the tip of her tongue over her lips. She had to, to catch the last trace of coffee. No other reason at all. So he really shouldn't be looking at her as if he's about to drag her across the table. That would be a total over-reaction.

"Shall we dance, Kate?" _Kate_? He never calls her Kate. Okay, that's because she said she'd shoot him in the mouth if he tried. It sounds rather good on his tongue. Like he's licking up the length of the K. Or the length of her legs.

"Why not?" She tries out a particular form of smile. This one says _Show me your moves_. The answering look appears simply to say _urg_? She could get used to this. In fact, she could get both forms of payback in. On present evidence, she can keep Castle speechless all evening. Win-win. She undulates into his arms and proceeds to take cognisance of the music. Ah. Waltzes. How very… romantic. She vaguely remembers that a long time ago the waltz was banned in polite society for being far too erotic. Mmmmm. There's a thought. Undulation very discreetly curves up and down Castle's surprisingly firm frame. Well. Surprising in all but one area. The firmness of that area is not a surprise at all. When she very slowly undulates once more she finds that big hands are very capable of stopping all forms of undulation in favour of holding her in as tightly as is possible while still dancing. That's a shame. She'd been enjoying herself. So had Castle, from the feel of him. And now he's not letting her play any more. She looks up through her lashes, bites her lip, and pouts. Ow. Now she'll have fingermarks on her back.

"What are you _doing_, Kate?" He sounds quite flustered. Smooth Castle, totally ruffled. She smirks happily. She loves being on top. In all sorts of ways.

"I'm dancing. You know, slow slides, moving to the rhythm, perfectly in harmony." He breathes. Very slowly and deeply. She's just congratulating herself when it falls apart. He slides his hand very slowly up her back, encouraging her head on to his shoulder, and then starts to murmur in her ear.

"I'm a great believer in slow slides. So much more satisfying for both partners. A perfect opportunity to demonstrate skill and control. Much more fulfilling than a short, sharp encounter."

She won't blush. She will _not_.

"Kate, you look a little – flushed." She's blushing. Dammit. "Is everything okay?" Syrup oozes less thickly than his totally faked concern. He knows exactly what's wrong. And sliding his hand down like that isn't doing anything at all to cure it.

"Just relax, Kate. I'll take care of everything. After all, this is our first date. I want you to enjoy it." Her feet falter. Castle's arm prevents her tripping. Or treading on his toes. Not smooth, Kate. Not smooth at all. She knew he'd try to call it a date. That's not the problem. Well, not much of one. Well, one she could have dealt with. By shooting, if required. The problem is that he's said it's the _first_ date. Which implies more of them. That hadn't actually figured in her thinking. One and done. Dates, that is.

How's she on the back foot, suddenly? She'd had this evening all worked out and now he's turned the tables. No. She's going to turn them back. She just hasn't worked out how, yet. Definitely _yet_. She'll just relax into his embrace and think about it. Slowly. There's no hurry to extricate herself. None at all. And how good this feels has absolutely nothing to do with her sloth. Nothing. She'll simply let him lead her round the dance floor and stay snuggled in and enjoy herself. Sorry? Did she really just think that? _Let him lead_? There's definitely something in his aftershave. Mind altering substances, perhaps. Anyway, it's only dancing. The man's supposed to lead. All her dance classes had made that clear. Eventually, she'd even managed to let it happen. It had only taken her two years. No time at all, really. And he's a good dancer.

Several leisurely revolutions of the dance floor later, Beckett still hasn't lifted her head off Castle's shoulder. True, he doesn't exactly seem inclined to let go of her either. She's fairly certain that spray body paint would be closer to him than she. Fairly certain. She still hasn't entirely worked out how to turn the tables on him, yet. His grip has altered from a classical ballroom dance hold to an arm round her shoulders and a hand splayed widely over the laces across the satin skin of her back. His little finger is placed very, very precisely one millimetre below the point where the fabric of her dress stops. That would also be one millimetre below the dimple of her spine. And that same one millimetre above arrest for indecency in a public place.

She doesn't know what insanity possessed her. She has _no idea_ why her body thought it would be a good plan to nuzzle into Castle's neck and then to kiss it. Not just kiss it. Kiss it with a swift flick of tongue. Mind altering substances. That's her excuse and she's sticking to it. Her mind had nothing to do with it. Her mind would have stopped her. Her mind is no fun. If she'd listened to her mind she wouldn't now be being helped into her wrap and escorted out the door. She wouldn't – quite – call it being hustled. But it's certainly very brisk. She is, however, considerably surprised that Castle stays rigidly to his own side of the town car. Didn't he like it? She'd had the very clear impression – impressed right between her thighs – that he'd liked it very much. Humph. Well, if he's going to sulk over the other side of the car, and not pay any attention to her at all, so can she. She glares out the window, metaphorically incinerating passing tourists and buildings as they go. This is not how a date is supposed to go. Humph. She will resolutely not be disappointed that he's not interested. He could at least have made conversation.

When the car pulls up at the door to her block Castle hasn't laid so much as a fingertip on her. He politely opens the door for her, says something she isn't listening to, to the driver – it'll undoubtedly, based on the journey, be _I'll be back in a few moments_ – politely escorts her into the block, politely escorts her into the elevator, and politely escorts her to her door. Perfect politeness. She hates it. She unlocks her door and he politely swings that open for her too. Any more politeness and she will – perfectly politely – scream.

She turns round to say goodnight. Politely. She just has time to notice that the door is swinging shut with Castle on the inside of it before he's crashed down on her mouth and evincing more arms than a hyperactive octopus. All of which arms seem to be totally focused on pressing her close enough to him for the dress to become a tattoo. He doesn't seem uninterested now. Oh no, definitely not uninterested. Much more of this level of interest and she'll feel like the newest exhibition at the Met. Almost equally capable of speech and movement, too. _Oooohhhh_. With considerable difficulty, she pulls some game on and her lips away. Just for a moment.

"Thought you'd got bored of the evening, Castle." He produces a look of disbelief that might nearly register on the bottom of the Beckett glare-scale. He'll need a lot more practice actually to make it there.

"Bored? _Bored_?" His voice moves from baritone to falsetto squeak in four syllables.

"You stopped dancing. You stopped talking to me. I thought you were sulking." But she's moved her voice to husky, breathy and seductive. It's wholly clear why he stopped. He clamps his mouth shut on something that looked as if it was about to be a stream of consciousness denial, takes a long, slow, deep breath, and runs a long finger very delicately all the way down her spine from her neck to her ass.

"It seemed to me that _you'd_ got bored of …dancing. Slow slides didn't seem to be… satisfying you any more. You seemed to have a …taste… for something else." She wriggles. That deep timbre penetrates her skin and vibrates through her flesh. Very particular flesh. Currently very damp flesh. "But it's terribly tacky to be making out in the back of a car, at our age." _Our age_? He's ten years older than she. _Our age_? "Especially on a first date."

It occurs to her rather too late that opening her mouth on indignant answers was exactly what he wanted. He's got a hand in her hair and his tongue is exploring and plundering and taking anything it wants from her including some very impolite noises and his other hand is curving around her ass and holding her entire lower body close enough to work out that he wears boxers without even looking.

Tuxes do have a disadvantage, though, she realises. It's all very well having your hands up the back of his jacket, but when you come to want to investigate more interesting areas, there's a cummerbund getting in the way. Still, she's intelligent and well-educated, and dextrous from hours of piano lessons when she was younger. (she'd hated it then. Now, it seems to have had a purpose. Just not the one intended.) She can undo this annoying garment. And if not, it'll tear. It's not as if he can't afford a new one.

It hits the floor with a satisfying swish, swiftly succeeded by a satisfying growl from Castle. If he makes any more comments about _first dates_ she'll maim him. Just enough to make a point. She wouldn't want to do anything too extreme. He might stop.

Suddenly there's a looseness around her torso. Ah. The laces aren't so tight any more. In fact, they aren't there at all any more. Oh. This is _not fair_. She's supposed to be in charge. But he's doing what she wants so she doesn't need to say anything at all. He has very clever fingers. Very clever. And said fingers are currently doing very clever things under the rear of her dress. Well, two can play at that game too. Her fingers are just as clever. She proves it, by undoing a strategically significant button. It's only fair to loosen tight clothing. This time the growl is a lot more dangerous.

"You wanna play that game, Kate? Okay, let's play." He kisses her hard, until she's short of breath, words, and dexterity. Then he starts to move down her neck, dipping her backwards for access to the hollow at her throat, nipping on her collarbone. When he runs his tongue along the edge of the neckline she gasps. When he runs it underneath, she whimpers. She'd return the compliment, but she can't.

"Like me doing that? I like doing that." She can feel the wicked smile. "I like doing this, too," and he pushes the dress down so she's left in panties and heels. "Do you like that?" Beckett abruptly recovers some game, at the teasing tone. Just because he's reducing her to a puddle of lust doesn't mean she's putty in his far too knowing hands.

"I like doing _this_," she purrs, and pushes his dress pants down with particular attention to the movement of the front placket. It's Castle's turn to gasp. His fingers seem to have lost all cleverness, suddenly. Ha. That'll teach him that he can't have his own way… _Ohhhh_. Maybe she should let him have his own way if he's going to put his mouth on her breasts like that. She'll save her payback for another time. She doesn't need to use it up right now.

"Where's your bedroom, Kate?" Bedroom? Oh yes. She's got one of those. Yes. Good plan. Her knees are just a little wobbly. She steers him in the right direction, only slightly distracted by his fingers, which are doing things that really ought to wait for the bedroom. Unless he's planning to pick her up and carry her. But that might mean his fingers would stop. On balance, she'll unwobble her knees for the few yards it takes. _Ohhhh_. Or not. She'll just stagger. If he puts his fingers _there_ again he'll have to carry her.

Her legs hit the back of the bed and she gratefully falls on to it. Now that she needn't worry about technically complicated matters such as standing up, maybe she'll have half a brain cell left to worry about how to get payback.

Or maybe not. Because Castle's now kneeling between her knees smirking up her body though there's enough heat in his eyes to cause burns and _oohh_ is that what he's been hiding under his button-downs? _Mmmmm_. Yes please. She arranges enough brain cells into order to try to sit up. Purely to admire, of course. And when she's finished admiring visually, she'll admire tactilely. Or should that be tactically? She can think of several tactics to admire him tactilely. Okay, both. Tactile and tactical.

His mouth is back at her breasts, and _oh_ when he does that with his tongue, when he rolls her nipple and then _sucks_, _oh _ that shouldn't be allowed: it's just as addictive as drugs. She won't be notifying the DEA, though. She'll just hang on to her own private pusher. Push. Yes. Please push.

It seems he has some rather different ideas. He's slithering his mouth downwards and nipping very gently which is tickling down her nerves and she knows what he's going to do and she still hasn't managed to sit up. She tries. She gets at least an inch towards it before he pushes her back down.

"That's not a good idea, Kate." Huh? He gets to look and she doesn't?

"Yes it is." She tries to sit up again, and is more firmly rearranged.

"Back down. Relax." He runs a hard finger across her and any thoughts of sitting up depart at speed. Any thoughts, in fact, depart at speed. Other senses have taken over. Touch. And hearing. He's murmuring some totally _filthy_ suggestions about what she might like him to do. And then he's doing them.

No. Thought returns, briefly. She is not – for once – going to issue any instructions at all. She is going to _save_ her payback. He's not tricking her out of it like he's tricked her out of her clothes. Absolutely not. This isn't payback time. This is all Castle's idea. It's he who had to put up an evening out. If he wants to finish it like this... she's certainly - _oooh - _not objecting. She says nothing. Nothing intelligible, anyway. There's suddenly quite a lot of noise.

He's found a game to play. No board or counters required. Just himself. Specifically, his fingers and tongue. She thinks it might be called _let's make Kate very, very happy_. Or possibly _can I make Kate scream?_ He can keep playing. All night. As long as she gets a chance to play too. But not until he's got bored of it. She'd hate to take his toys away before he'd finished playing – _ohhhh Castle_ – with them.

Oh. He's got bored with his game. Her turn to play. She reassembles convenient accoutrements such as muscle control and tries to move. Hmmm. Maybe muscle control was a little too much to ask for after the third screaming orgasm. She'll never be able to order that cocktail again. Then again, she may never need to. Why settle for a drink?

Somehow it's not her turn. That's not fair. She wants a turn. He's slid up beside her and it's perfectly obvious what he thinks is the next step. Something about the way he's looking down. Oh yes. And the way he's spreading her knees and moving across her. Well, _no_. She wants a turn first. She does. Really. And she's trained in some very useful defence skills. Okay, so they aren't normally – ever – used for this, but needs must.

She reaches up to Castle's neck, strokes seductively up across his jaw, curls her fingers round his shoulder – and pushes _hard_, pulling the arm he'd been leaning up on out from under him and leaving him flat on his back. Payback time. Except she's not using up her payback this time. This is just ...reciprocation. Shouldn't take and not give. She wriggles partway over him in a way guaranteed to leave his knees weak, which now she thinks about it is fairly pointless because it doesn't matter that he can't stand up. Only one bit of him needs to stand up right now.

* * *

_Well, thank you all very much. I'm glad you seem to like it! Please do let me know what you think, because it helps me write the next one!_


	3. Chapter 3

**Chapter 3: Sold to the lady in the red dress**

It's standing up quite nicely, but she's sure a bit of encouragement won't hurt. Well. It'll only hurt in the best possible way. Her hand slides delicately over the area of his chest that she isn't lying on. He might be upset if it doesn't get some attention. She'll just ensure that's not the case. She tastes along his collarbone. Then she nips, just hard enough to be noticeable. Then she moves her mouth down a little, and simultaneously moves her hand down too. That combination had a remarkable effect. When she'd licked his nipple and stroked around and over his hot weight he'd reacted most enthusiastically. Far too enthusiastically. She's flat on her back being pinned down and he's poised ready right where she really, really needs him and it's still _not fair_ that she didn't get a turn.

On the other hand, she can defer her turn in favour of the many advantages – _ohhh_ – of slow slides. He feels really, really good. He's certainly really, really good at _moving to the rhythm_. And at slow slides. Though she could deal with faster, harder slides too. She slips her hand over his excellent ass and provides some encouragement by way of a well-judged scrape of fingernails on a sensitive area. He gasps something that couldn't possibly be printed in a family newspaper and thrusts much harder and _ohhh _ that feels unbelievably good. She lets the sensation overtake her and doesn't care about the noises she's making just as long as he won't stop till she's satisfied. Satisfaction overtakes her shortly after sensation.

Castle is quite clearly also wholly satisfied. Nice manners, too. He's not squashing her. He might be surprisingly well toned, but he's still heavier than she is by some distance. So it's good that he's rolled over and – oh! He's taken her with him. She's just a little offended that he can still think. At all. Not that she wants squashed. But a little evidence that he can't think would be… flattering. And she still hasn't had her turn. She acquires a very slow, wicked grin. What's that saying about birds and stones? As a writer he should really appreciate her use of the metaphor. Even if she won't be saying it. She's got good manners herself. She never talks with her mouth full.

She squirms slowly and extremely seductively down his body, paying particular attention to leaving a leisurely line of wet kisses and intricate patterns from clavicle to navel. Then she stops. She's perfectly certain that he's paying total attention to what she's doing. He's absolutely rigid. With tension, of course. Mostly. It takes him a noticeable amount of time to be able to speak. Something to do with his inability to breathe evenly. Or possibly the words got lost in the groans. Shame this is a totally inappropriate way to keep him quiet anywhere except absolute privacy. Though there's a lockable storage closet in the Archives floor…

"What are you _doing_, Kate?" How odd. She thought he was extensively experienced. He's certainly displayed considerable experience and finesse.

"Don't you know?" She points the moral by slipping down another few inches and drawing a moist line with her tongue to one inch above immorality. "I'm disappointed in you, Castle. Clearly you have no imagination. Isn't that a bit of a problem for a writer?" There's a squawk, which becomes notably strangled when she takes a small nip at a nicely cut line of quadricep.

"I have plenty imagination. I can imagine lots of things. I just want to know which of my imaginings is about to happen."

"It'll be a nice surprise for you. Don't worry, Castle." He looks abruptly terrified. "This isn't my payback for buying you. That comes later." Oops. Perhaps that wasn't the best thing to say. He's… er… deflated, somewhat. Oh well. She knows how to fix that. She smirks at him, and then runs the very tip of her tongue over her lips. Then she slides her finger into her mouth. Then slides it out, adding a twist of her tongue that should be declared illegal for excessive wantonness. There. That's fixed it. Oh yes. Impressively. Now for the fun part.

She repeats the tiny lick across her lips, fractionally above his thigh. It's entirely coincidental, anatomically, that it's fractionally _not_ above other areas. When she repeats the twist of her tongue he makes a noise that belongs in the lion cage at the Zoo. Matters – and Castle's control and vocabulary – go rapidly downhill after that. Right into the gutter. What a shame. He's normally so suavely sophisticated. It's very … satisfying… to reduce him to incoherent wreckage. Very. She's back on even terms.

Well, she was. But now she's all wrapped up and quite unable to move out his arms; pillowed on his firm chest and still completely naked. It's – nice. Comfy. She could get used to it.

What? They've been on _one_ date. Okay, so it's been spectacular. And she still hasn't used up her payback. But it's one date. But Castle's cuddling her in like he's never going to let go. But it's one date. But it feels really, really good. But it's one date. She falls asleep, still cuddled in, to the chattering of _buts_ wheeling round her head. She dreams of _buts_ flapping round her like bats, and wakes completely confused. Bats in her belfry, in fact. Though Castle is still here. Still wrapped round her. And, it seems, very, very happy still to be in bed with her. But… she has to go to work. Rats. (Not bats.)

Castle makes it very clear that he thinks that getting up and going to work is a bad idea. He suggests a number of apparently better ideas. Some of them sound rather interesting. Later. One idea, however, is both possible, practicable, and performable. Though it turns out that her shower is quite small, when asked to fit two people rather than one, and especially where – er – athletic activities are concerned. And she's sure that a heated shower wall wouldn't go amiss. There must be a market for that, among rich New York glitterati. Right now, however, she'd settle for one very particular purchaser, who's washing her with considerable attention to detail and absolutely wicked fingers. She's soaked. And Castle murmuring in her ear about all the ways he can wash her and all the places that need attended to and punctuating it all with little kisses and soft strokes and slow slides of his fingers is really _not helping_ her get ready for work. Or indeed get clean. Or dry.

Kate manages to detach Castle after a shower that only took four times as long as normal and involved threatening him with amputations to allow her to have some chance of reaching the precinct before shift starts. He pouts and whines and produces huge, appealing puppy dog eyes; none of which have the slightest effect.

"I have to get to work, Castle." Pout. "Killers don't just walk into cells by themselves." Pout. Kate resorts to negotiation. "What will it take to get you to let go and let me go to work?"

Castle grins happily. He looks like he's won the goldfish at the fair. "Well, Kate…" - she fears the worst – "I want you to come on another date. A proper one." She looks at him open-mouthed. He takes shameless advantage of it, swooping down on her open lips and kissing her enthusiastically. He's only detached this time when she twists his ear.

"What do you mean proper one?" She'd thought that it was a proper date.

"One where you haven't bought me for the evening. I feel very used that you felt you had to buy me."

"That was the dinner I paid for. At your request. You begged me to save you."

"I paid for it!" says Castle plaintively.

"You still begged me to save you. Oh, Castle. You have no idea how _used _I can make you feel. I haven't even started on the payback yet." She grins nastily. "I still need a maid." Castle winces.

She looks at her watch and squawks. "I have to go." Castle hangs on to her.

"Not till you agree to come on another date." Kate glares fearsomely. It has no effect. "Or I could ask you in the precinct in front of Ryan and Esposito. Don't you think they'll start asking questions if I ask you to come on a _second_ date?"

Dammit! He's got her there. She doesn't have _time_ to think of a counterargument. She needs to go. Now. "Okay. But we are _not_ done with this discussion."

Castle smirks infuriatingly and slopes off home with a posture indicating completely smug satisfaction. When he turns up at the precinct later Kate favours him with a glare that should set his socks and shirt to smoking and is more than usually sarcastic. Not one iota of it dents Castle's happy demeanour by so much as a smidge. That doesn't improve Kate's mood, either.

On her way home, alone, (which is perfectly satisfactory. Really.) she comes up with an idea. Castle's asked her on another date. But this time, she should be able to choose where they go. Or, more pertinently, _don't _go. One evening out in Manhattan, courtesy of a well-reported charity fundraiser, was quite enough page six exposure for her. So instead of going out on a date, it might be sensible (and discreet) to stay _in_ on a date. The fact that there would be no more silent taxi rides has nothing to do with that idea. She concocts a text.

_I don't want to go out on a date. I'd prefer to stay in._ Response is remarkably rapid. Castle must be procrastinating over his laptop again. How does someone who never appears to write at all manage to produce so many books? Twenty six? That's more than one a year. She looks at them all sitting innocently on her bookshelf, and glares at them on general associative principles, since their author isn't there to receive his own well-deserved glares.

_Okay. Your place or mine?_

That is a good question. She's sure that Castle's bedroom is the definition of metrosexual luxury. She's _also_ sure that his shower won't be so small that she bruises her elbows on the walls. Should she be feeling… athletic. But she doesn't feel like dealing with an audience.

_Depends. Do you normally take your family on dates with you?_ There's a lengthy pause in correspondence, during which time Kate makes dinner, watches a movie, and reads three chapters of her current book, more or less concurrently. Which book, just for reference, is _not_ by Richard Castle. That was two days ago. And possibly tomorrow.

_No. So Friday's date night. Mine, 7.30._

_What if I'm already on a date Friday?_

_You better ditch him. Anyway, I'm much more fun._

_You better make it worth it._

_Oh, I will. You just wait._

It's entirely unfair that two days' waiting also involves two days of heated innuendo around Castle's cooking skills. She really didn't need to know about his appetite for spice and the need to taste the main dish as often as possible. She spends the whole two days in a state of barely-suppressed arousal and consequent frustration. But she's not the only one. She's left Castle in a state of not-at-all suppressed arousal and considerable frustration. He really shouldn't have followed her into the break room. It was completely accidental that she burnt her finger. The first time it was authentic. By the third, however much Castle knew it was false, he couldn't take his eyes off her finger between her lips.

She turns up on Friday completely confident that she's reduced his suavity to smithereens. But just in case he has a few remnants of it left, she's put on a dress. It's a flattering colour – deep dull green – and a flattering cut. Its hem is also a clear six inches above her knees.

Dinner doesn't happen. It seems that Castle's hunger has not turned to thoughts of food. Eating is on his mind, though. Very much so. That man can do things with his mouth that wouldn't have occurred to the snake in the Garden of Eden. Even without his tongue being forked. Playing with your dinner is generally regarded with disfavour, but Kate is very sure she can forgive that. Especially as she gets to play with hers. And then they start to play together, and everything else is forgotten in hot touch and enticing strokes and duelling mouths and tongues until he pushes into her and she cries out and he _moves_ and that's _ohhhh_ so good and _ohhh Castle_ and his fingers circle her and_ please now don't stop_ it all shatters and she has no idea where he stops and she begins.

He's saying something. She mutters vague positive words. She has no idea what she's answering, and she's too pleasurably exhausted to care. Three seconds later she's sitting bolt upright and considering justifiable homicide.

"I will not!"

"But Kate, you just agreed. You promised." He looks saintly. She considers hitting him. "You can't break your promises. You said you'd come out on another date." He looks ridiculously appealingly at her. It's rather spoilt by the fact that he's barely managing not to laugh. She burrows into the pillows and sulks very audibly at him. He stops trying not to laugh, and chuckles deeply. It's entirely unfair that his chuckle conveys a considerable amount of _gotcha_ and even more male satisfaction at the evening's progress. Suddenly she remembers that he still owes her the payback.

She emerges from the pillows smiling like a crocodile. Castle's self-satisfaction leaks away in instants and he's looking very, very nervous. Good. She'll just let him stew. She stretches languorously and keeps smiling. The stretch doesn't have the usual effect. Ha.

"I'll let you know the payback when I next see you," she says, freighting it with unspoken but doom-laden significance. Castle looks even more frightened than a moment ago. Then he clearly realises what she's just said.

"You're going?" Kate nods.

"It's my bedtime." Castle's face falls.

"You could stay," he says very hopefully.

"I don't want to have a walk of shame past your family tomorrow." Castle looks pathetically at her.

"Really?"

"Really."

"In that case, we'd better agree where our next date is." He stops looking pathetic and replaces it with predatory.

"I didn't agree to another date," Kate says weakly. She's not going to be tricked into more dates. He shouldn't be asking when she isn't capable of making a reasoned decision. He should ask when she's fully conscious. Which is not when she's sprawled across a bed still in aftershock. And now he's drooping pathetically at her and using the full-on puppy dog eye expression which is entirely _unfair_ because somewhere in her cortex is a hard-wired reaction to that face which is to give him whatever he wants. Especially as she'd be quite happy with another date. _After_ she's paid him back.

"You did, Kate. You can't leave me all alone and unhappy." She glares. For good measure, she rolls her eyes and glares again.

"I'm not deciding anything now. You cheated." But there's a little smile starting to quirk the corner of her mouth. "Anyway, you still owe me for saving you." Castle's suddenly looking nervous again. Kate grins evilly. "I've got some ideas about that." She manufactures a completely and obviously faked expression of sudden realisation, which her continued nakedness does nothing to diminish. "I'll only come out on another date with you if you manage to complete the tasks I set you to my total satisfaction."

Castle's mouth drops open. He gibbers. Not a word of sense escapes his lips. "B…b…but…but…but…" Kate quirks an eyebrow at him and continues to grin.

"You said _Anything_. So that means anything I choose. I could request a trip to the Moon. Or the Hope Diamond, in a pendant. Or you to ride a police horse naked, again, or dressed up as Little Bo Peep. Or a packet of M&Ms." She sniggers. She's had a thoroughly satisfying effect on him. "Point is, it's up to me." She sits up. "I'll tell you Monday. Or when you next come to the precinct." Castle is lying on the bed with a pillow over his face. His body looks utterly disconcerted. Flat, she might say. Or flaccid.

She gets as dressed as she can stand – her panties are a lost cause – and slinks round the bed to pull the pillow off Castle's face. "I'm going now," she purrs. He stares pathetically up at her. He looks like a trapped mouse.

"Why do you torture me so," he whimpers. It's nearly as heartfelt and sincere as Kate's request for a trip to the Moon. What would she _do_ there? Though low gravity might have some interesting effects. Mmmmm.

"Oh, Castle. Because I _can_." He tries for a growl, but it's still pathetic. Or bathetic, more like. Snigger. A little extra torture won't hurt. Physically.

She sashays closer to Castle and kisses him thoroughly, slowly and seductively; evading his grip and further sashaying to his bedroom door, idly swinging her panties from the tip of one finger. Seems Castle's whimpering again. Her walk increases both the amplitude of her hip sway and its air of smug satisfaction. Entirely accidentally, of course. Entirely.

She's got a plan. She happily works it out over the course of Sunday, refines it, enlists the aid of Google – you can find _anything_ on Google – makes some careful preparations, and swings cheerfully into the precinct on Monday. This'll show him. She giggles. It should be a snicker but somehow it's mutated to a giggle. Ooops. And here's Castle. He's looking pleasingly terrorised. Good. She greets him with another crocodile smile. He cringes. This time she snickers.

He's getting more and more nervous the more she smiles. He twitches, and fidgets. It's intensely satisfying. He pleads pathetically in a very quiet undertone. That won't work. She manages to continue the torture till a very precisely calculated 3.55 pm.

"Okay, Castle." He whips his head up to stare at her. "Your mission, should you choose to accept it" – Castle grins appreciatively.

"Such a geek, Beckett." –

"starts here." She hands him her apartment keys. His jaw hits the floor. "You have until I get home to fulfil the tasks on the list I've left in the apartment." He looks happier. That won't last. She grins very evilly. "First, of course, you have to find the list."

"What?"

"You spend all your time pretending to be a detective. Well, detection isn't about insane theories, it's about logical deduction. So, you have to follow the clues and find the list." Pause. "Shift finishes in an hour and a half. I'll be back at 6.30." She never knew he could move that fast. That should induce considerable fretfulness. Her paperwork suddenly seems a perfectly pleasant way to spend the afternoon. No fuss. No trouble. No silly theories. And the happy thought of Castle buzzing around like an Ecstasy-hyped hornet, getting more desperate by the minute. She snickers, again. She won't be unkind, though. She won't leave early, she won't take a cab home, she won't disturb him or distract him. And – whatever happens – she'll still go on another date with him. Many dates, in fact. She just doesn't need to let him know that. A little competitive tension won't… disincentivise?... him. Rather the reverse. She'd better dial the good humour down, though. Ryan and Esposito are looking at her very strangely. She glares. It works.

Shift finishes, but there's no need to hurry to pack up. Kate ambles from the precinct via some window-shopping to the subway and doesn't exercise her elbows to squeeze on to the fast train. She won't cheat. She's not Castle.

* * *

Castle has, courtesy of a considerable experience of sci-fi conventions and general dorkishness, followed Kate's clues with general exactitude. Some of them were really very clever. Some were just plain mean. He finds the all-important list with less than half an hour to spare. It's neatly folded into an envelope. He reads it with disbelief.

_Your tasks are: 1. to order my favourite Thai dish and whatever you want for dinner. 2. to sit in my apartment, in my bedroom (except when dealing with the delivery), without investigating my underwear drawer, which is the top left hand drawer of my bureau. See you later. KB._

The first bit is actually not that difficult. He's seen the detritus of late nights, and he knows pretty well what she orders. The second is _incredibly _mean. It's like saying don't think of pink elephants. You always think of pink elephants. You can't _not_ think of pink elephants.

Kate Beckett is truly diabolical.

* * *

_Okay. So which of you expected that challenge? And is it a good payback? And what do you think will happen next?_

_Thank you all for the reviews and favourites and follows. I appreciate all of it, and hearing from you. _


	4. Chapter 4

**Chapter 4: Payback**

Castle orders dinner, borrows a book from Kate's shelves and repatriates himself to her bedroom. There is no chair. He can sit on the floor or sit on the bed or bring a chair from her dinner table in. The bureau smirks at him. Just like Kate would. His eyes are instantly drawn to the drawer in question. The _handle_ is smirking at him. At any moment it will become the face of Jacob Marley aka Kate Beckett. It's even tantalisingly not-quite-open but a fraction off fully shut.

Castle sits down on the bed, turns his back on the bureau, and opens the book. Ten seconds later he fixes the bureau with an attempted glare. He's sure the drawer was further open than it was. He turns away again. Another ten seconds passes. He's sure he hears it opening, but when he flicks round it's not doing anything at all. It looks unwarrantedly innocent, but he knows it's just biding its time. And so the time passes, punctuated only by the minute or two it takes to deal with dinner. He keeps his back firmly turned to the drawer.

He's never been so glad to hear the door open in all his life. Sitting in Kate's bedroom, on Kate's bed, with Kate's underwear drawer in reach and constantly at the front of his mind, is the nadir of torture.

* * *

"Hey, Castle." Kate appears in her bedroom doorway, casts a brief glance around, and smirks. "How was the book?" Castle growls. "I see you found the list." Her smirk could now be tied round Alaska with room to spare. "Have you had fun?" Maybe that last wasn't the best idea. Castle pounces on her with remarkable speed and kisses her till she squeaks. Is that supposed to be a punishment?

"You are _mean_, Kate."

"And you peeked." He lets go of her, fast. She steps back, so he can't grab her again and notice any mirthful quivering.

"What? I did not! I never touched it!" She preserves a perfect poker face. It takes her considerable effort.

"It's open. I left it shut. Didn't you even bother to cover your tracks?" Those drama classes in high school are coming in really handy right now.

"I did not. Check it for fingerprints. You won't find a single print of mine on it." Does he really think that will play in Peoria? He's been around the precinct for weeks. Surely he must know that she'll expect him to have the nitrile gloves available.

"Proves nothing. You've had enough crime scene experience to remember to use gloves." Oh, this is so _easy_. If only preserving a bland demeanour was as easy as winding him up.

"I didn't. Why won't you believe me?" His voice is beginning to take on a higher pitch. He finally remembers to look round at the drawer. It is indeed half way open. This is just downright marvellous. He's so wound up it's untrue. "I never touched it!" he says again, with the same intonation as an unjustly accused child. She's never heard him actually squeak with indignation before. If she wasn't concentrating so very hard on keeping a straight face she'd already be doubled over on the floor with laughter. Though that's not far away.

"Well, who did then? The underwear pixies? You were the only person here. I left it firmly shut. Now it's wide open. Unless you're telling me you let the delivery man into my bedroom?" She's particularly proud of that last line, delivered with absolutely the right note of horror.

"No! Of course not! He didn't even get past the front door." Kate raises an eyebrow sceptically and rolls her eyes.

"So if it wasn't you, what was it? Ghosts? Poltergeists? Little green men from Mars?" Castle looks blank. "What, no way-out theories?" He shakes his head dismally. "Must have been you. Guess you just couldn't resist temptation. Which set did you like best? Black? Scarlet? Pure" – she drags the word sensuously over her tongue – "white?"

"I never saw any of them. Really I didn't. I don't know how it got open but it wasn't me." He sounds really upset that she doesn't believe him. She pats him consolingly – but very patronisingly – on the shoulder.

"I suppose it was unfair," she says sadly. "I should never have put such a strain on your self-control. Offering you the chance to rummage through my underwear drawer… Nah. Couldn't expect it. There is one thing that I find a bit strange, though."

"What?" Castle's drooping miserably.

"How come, when neither of us have touched it since I got in, the drawer is now wide open?" Castle spins round. The drawer is now wide open.

"It's a poltergeist!" Castle takes a couple of fast strides _towards_ the errant drawer.

"Aren't you worried about it attacking you?" He completely misses the undertone of uncontrollable amusement in Kate's voice.

"Beckett, it's a real live poltergeist!" He sounds like he's won the lottery.

"I thought poltergeists were, by definition, dead?" she says dryly.

"This is wonderful! You have to come see. We need a trap. Imagine the ramifications!" He's almost reached the drawer. Kate gives up all semblance of control. Castle's so enthused by the possibilities that he doesn't even notice. "What can we catch it in? Have you got a jar?"

"Would it go in a jar?" Kate says very unsteadily. This is delicious. It's wonderful. In about five seconds it's going to be _fabulous_. Oh, payback is so sweet. Castle's made it to the drawer. He turns round to look at her.

"Of course it would go in a jar. Ectoplasm compresses almost to nothing. Just like Ghostbusters."

"Are you Bill Murray?" She receives a glare.

"No. I'm far braver and better looking." Snort. Snurgle. Keeping any sort of control over her boiling-over mirth is becoming a lost cause. Get on and _investigate_, Castle. It'll all be spoilt if he delays much more and she explodes in giggles. Snurk. He peers into the drawer. She's making for the door as there's a noise of enraged elephantine proportions.

"Beckett!" Ah. He's found it. She's laughing so hard she can barely walk.

"Yes?" she snorts. "Something wrong?"

"You… you… you are _despicable_! You set me up. You were horrible to me. You deliberately made it look like I'd been peeking."

"Wouldn't you have?" It's difficult to speak through her gales of laughter. She collapses on to the couch and tries, very unsuccessfully, to stop laughing for long enough to breathe. "Oh, your face. Oh, I should have taken pictures. Oh, that was _so funny_." She snurks and snorts and snurgles and fails utterly to stop laughing. "Don't you like my contraption?"

He comes barrelling out of her bedroom with a tangle of springs and levers and makes straight for her. She's still limp with laughter and doesn't get out the way fast enough. Next thing she knows he's grabbed her giggling form and is imprisoning her on his lap. Not the worst outcome in the world.

"You deliberately set me up." She nods, happily. "You set it all up. You tricked me. You really made me think I'd failed your test." She snickers some more. "You never meant any of it, did you? You just wanted to wind me up."

"Yep," she says cheerfully. "And I got you but _good_. Shall we have dinner?" Oh. Somehow getting up doesn't seem to be happening.

"Not yet," Castle says direfully. "You were mean. You didn't play fair. In fact, Beckett" – Beckett? Uh-oh – "you cheated. And now I've got you. You can't move." Oh. She can't. That's not playing fair, either. He hadn't looked so toned that he could stop her pulling away. Not that she'd been doing a lot of looking, lately. She'd had some difficulty keeping her eyes open. And the angle of her vision hadn't been too helpful, either.

"You said _anything I wanted_, if I'd only buy you out of the clutches of the sharks at the fundraiser. Stop complaining. I got what I wanted. I completely pranked you. And now you're just being a sore loser." There's a growl under her ear, which is currently (how? She didn't do that – did she?) tucked against his chest.

"But I didn't lose. I completed the list. So I won. So you have to come out on another date. That'll be the third date. Fourth, if you count the fundraiser. So we're dating. Officially." _What the hell_? She's squawking. She never squawks. She sounds like a constipated pigeon. She gibbers. She never does that, either. Now she's turned into some form of brain-fried monkey. She needs to get this together. _Dating_? Her brain fries again.

_That_ is entirely unfair. Now who's cheating, Castle? _Ohhh_. _Definitely_ cheating. She can't concentrate when he's delicately tracing a fingertip down into the vee of her shirt and undoing her buttons as he goes.

"You're my girl." There's enough male satisfaction in his voice to float Arizona. She will kill him. _His girl_? No way. If he ever says that anywhere outside her apartment she will dismember him. It sounds good though – what? Nonsense. Ridiculous teenagery possessive statements do not give her a warm glow. Oh. They do. Well, it shouldn't. So it can't. Sorted. So he can just lose that sexy smirk. He can stop undoing her shirt, too. Oh. He has. Good. Really. Oh. It's because he's run out of buttons.

"We are not dating." He smiles seraphically. She'd hit him, if she could free her hands. Tugging her shirt down her arms to stop her was _not fair_. Hot, but not fair – what? She doesn't know him well enough for that. _Yet_, says a seductive little voice in her head. It sounds alarmingly like Castle.

"Silly Kate," he smiles affectionately. _Silly_? She growls dangerously. "Of course we are. You don't have to tell anyone, though."

Phew.

"I'll do that." _NO!_ He grins. It bears a remarkable and deeply unwanted resemblance to her earlier crocodile smirk.

"I'll start with Ryan and Espo – oh, and Lanie. She'll kill me if I don't tell her first. Paula will need to hear, to manage the PR. The rest can wait. Well, except Mother and Alexis. Oh – and Captain Montgomery." She's squawking wordlessly but furiously.

He's tricked her again. He effectively stops her planned tirade by kissing her. How's she supposed to complain when his tongue's down her throat? She can't even complain that her shirt's now completely off. Her hands should not be encouraging him by holding him closer. He shouldn't feel this good when she's this angry with him. Ought to be angry with him. She'd manage to stay annoyed if he wasn't nibbling her ear, or kissing exactly the right spot on her neck, or palming her breasts with those wickedly large hands. It's very difficult to stay annoyed when she's panting. It's even harder when his mouth is moving naughtily downward and approaching the lace edge of her bra. She's failing utterly to de-fluff her brain into arguments – they are _not_ dating and he is _not_ telling anyone that they are dating – hold on, those are contradictory. If they're not dating there's nothing to tell.

Thought is thrown into chaos when his mouth closes over her nipple and he sucks hard through the fabric and then plays and worries and then, once she's making little noises, undoes her bra and nips at the undercurve, leaves the spot where later she's sure there will be a mark, and promises herself revenge or at least a matching mark. If, that is, she has enough brain cells – _oohh_ – to remember that.

He's stopped. Why's he stopped? Oh, okay. He's kissing her again and she doesn't even have enough brain left to do something about it. Like pull him closer. Or undo his shirt and leave some marks of her own. Or – _oooohhh_ – or... or... Or just let him do whatever he wants because it feels so _good_ and his hand is holding her up and the other hand is on her thigh and making her think some very, very dirty thoughts about what he'll do next and _ohhh_ she was right: he's dancing fingers over her dress pants and some very sensitive areas and she's _ohhh_ squirming against his hand which is entirely unfair because she needs both her hands to hold on to his shoulders and can't retaliate at all.

Which is undoubtedly why he's taken completely shameless advantage of her momentary weakness to undo her pants and insinuate his fingers on to the smooth silk of her panties and – stop. No. Don't stop. She knows exactly what his fingers can do. And she'd rather like them to get on and _do_ it. Now. Except he isn't. Worse, he's stopped kissing her, (which means that perforce she has stopped kissing him, which was not in the game plan) moved her away (which was _definitely_ no longer in the game plan because she'd had some plans, when she could focus her mind again) and stood up. That's not good. He surely can't be _that_ upset by her joke? If he were he'd not have started down this route. He's just teasing her. Humph.

He _was_ just teasing her. Because he's tugged her up and left her shirt behind and _ooops_ she's just fallen into him because she's tripped on her pants which have puddled round her feet. That's Castle's fault, too. If he hadn't tugged, she wouldn't have tripped. Not accidentally, anyway. Oh well. If you have to trip over you might as well fall into a nicely muscled chest and some rather strong arms. Even if he does still have a shirt on. She takes advantage of her misfortune (or something like that) and drops a moistly lascivious kiss on the open vee at his neck. There's an indrawn breath. She points the moral by undoing a few buttons, and nestles in. It's entirely reasonable that she should kiss his pecs. They are, after all, right there.

That's unkind. She was doing something _nice_. It doesn't happen often. He should just enjoy it. It's not on to run his hand into her hair and stop her kissing that nicely accessible chest and turn her face up just so he can take her mouth again. But she can put up with it for a few more moments. Or hours. Especially as they seem to have re-entered her bedroom. Three steps… two steps… one step – range. She undoes his pants in a trice, shoves them down and watches happily for the first fraction of a second as he trips on them and falls backwards on to the bed. Shame she forgot he was still hanging on to _her_. She lands rather harder than she'd like and they _oof_ simultaneously as the breath rushes out of each of them. It's not all bad, though. She's ended up sprawled over him, straddling an interestingly engorged area and with the option – which she instantly exercises – of finishing opening his shirt and undertaking a little more testing of her theory that if she nips his nipples he's going to enjoy it immensely. Last time didn't quite supply enough proof, really. More experimentation is needed.

Very little experimentation is actually allowed. Very shortly after she tries she seems to have ended up flat on her back (again) being kissed ruthlessly (again) and naked. (again) Though Castle is also naked. (again) There are some compensations… Another – er – compensation is making itself known to her. Forcefully. _Ooohhh._ Now if she simply wriggles a little that way and turns into him and brings her leg up round his waist like _that_ and slides… Oh yes. That feels just right.

"I like this dating thing." What? "I really like it." How's she flat on her back again? She opens her mouth. Castle withdraws somewhat and pushes forward again. What was she about to say? Oh yes.

_We are not dating._ That's what she meant to say. She did. So how did it actually come out as "Me too."? That was _not _what she meant to say. It really wasn't. But she isn't exactly getting a chance to use her tongue to form words. If she could articulate any words. He's so _good_ at making her feel good and he fits her just perfectly and he's hitting just the right spot and _please more_ she's probably scarring his back but _harder_ he really does not seem to mind and yes, there, now, _yes Castle._

Wow. Maybe this dating thing is a really, really good idea. She snuggles in – not that there appears to have been a choice about that, since there's an arm around her already – and tries to unscramble her brain. She feels that she's been tricked, again. How has it happened that he pleaded with her to save him from the shark shoals of seniors at the fundraiser, agreed to do anything _she_ wanted in return, and instead she's gone on two dates with him, promised to go on a third, and here he is in her bed again? Not that she objects to the last one. Oh no. That's not the point. She did him a favour, and how come it's turned into him getting exactly what he wanted? She was supposed to be the one getting exactly what she wanted. He's the one who wants to be dating. She just wanted payback.

_Ohhh ohhh. _ That's sneaky. Deceptive. Duplicitous. Delicious – _ohhhh_! He shouldn't be allowed to use his tongue like that. How'd he slither down there anyway? _Ohhh fuck_ that feels good when his fingers move and his lips and tongue move and _ohhh_ very careful teeth. Why does she care about payback anyway? It doesn't matter, so long as he keeps doing _that_.

"That's good," Castle smirks while she's still trying to recover thought and breath and muscle control. "I'd hate to think you were just using me for sex and nothing more." Huh? "Dating involves more than just sex, you know. I can get to know you." His body seems to know her very satisfactorily already. Best friends, in fact, their bodies. "Show you off publicly." She screeches. "Joking, Kate." She settles down again, grumping. "I think I'm going to like dating you officially." He starts to show her just how much he likes it, which turns into how much they both like it, which turns into a tangled mess of exhausted limbs and messy bed.

Dating, huh? She supposes, as she falls asleep cuddled into Castle's body, that it's not such a bad idea.

* * *

Six months later, by which time everybody knows that they're dating because Castle has no discretion _at all_, Castle lets it slip when she's muttering darkly that she has _no idea_ how she got into this situation - that he'd planned the whole thing. It had fallen wholesale into his head at the moment his mother announced he was for sale.

Payback's a _bitch_.

* * *

_And... we're done. Thank you all, I hope you've enjoyed it. Please let me know!_

_PS - I'm sure that if you try hard enough you can construct a timed drawer-opening contraption. If anyone works out how, let me know. For everyone else - please just go with the fictional flow._


End file.
